I prefer Supernova, as with that, I hit everyone (most of the time, when I'm not off on a side of the map). The lower per-target damage and healing is more than made up by increasing the number of targets hit. I expect that Focused Radiance might be better for high-skill use, though.

I really like the slow/haste on her ult for 1 mod token, it gives most of your team a chance to escape/reposition and slows enemies possibly leaving them out of cover.
I don't like using 3 mod points on an ult since you'll prob only use it once or twice. I'd rather use the other points to buff heals on my other skills.